The Hunter can be seen in a cube far above the cube where Marty and Dana reside during the pan out shot that reveals the assortment of monsters during their elevator descent into the depths of The Facility.

It was placed here because the directors originally planned to release Left 4 Dead exclusive DLC that featured the Cabin In The Woods cabin and facility. This idea was eventually scrapped when the company producing the DLC went bankrupt.

Very difficult to see in screenshot, but it has the same animation as an idle Hunter in the games.